The car in question is a European Accord with the N22A1 engine, which is a chain-driven DOHC diesel engine with hydraulic tappets. And the scary word there is "chain-driven", as this is a known weak spot with this engine. Honda says 0W30 oil is "preferred", then 0W40, and then 5W30 & 5W40 oils (ACEA A3/B4 or A5/B5). My current oil is Ravenol SSO, which is a PAO 0W30 with API SN, ACEA A3/B4, BMW LL-98 (approved), MB 229.5 (approved) and BMW LL-01 (recommended). With this oil, there was a very noticeable reduction in chain noise, compared to my previous oil, which was Ravenol FDS (the noise is more like scratching rather than knocking, hard to describe. Happens *after* a few seconds from starting, zero noise for those first few seconds, though when hot the noise is always there).
However the noise-reducing effect wore off after around 3.5K miles and the noise came right back. So I'm guessing the oil sheared down in that time enough to cause this (I can't prove this, idk where to do a UOA in Europe). Going with this logic, I figure a slightly thicker oil may help, so I've been looking at Ravenol SVS, which is a 5W40 with API SP, ACEA A3/B4, BMW LL-01, MB 229.5 and Porche A40 all recommended with no approvals(??). Ravenol also promises this particular oil to be very good at cleaning, although they don't mention how this is achieved (esters?). This oil is also somehow identical to Ravenol HST, sans the NOACK value. While the higher viscosity sounds good, I'm worried if I'd be sacrificing cold performace, since Honda really seems to love 0W oils in general. I don't expect lower than 10F temps though, so I'm not sure if 0W or 5W really matters. I've also been looking at Ravenol VMP, a mighty impressive oil, however I don't need a Mid SAPS oil, since no DPF, so I'm not sure if it's worth it.
I know y'all love the M1 FS 0W40, so I'm willing to try it, though there have been mixed reports on this very issue.
Here's the stats for nerds:
Ravenol SSO: TBN: 10,5 - SA: 1,1 - Flashpoint: 236C - VI: 173 - NOACK: 7,7% - Pourpoint: -60C - MRV(-40C): 17.400 - KV40: 68,6 - KV100: 12,0 - HTHS: 3,57 - HTFS: 2,61 - VII: 4,89% - A_Harman index: 0,9022
Ravenol SVS: TBN: 12,0 - SA: 1,19 - Flashpoint: 240C - VI: 173 - NOACK: 8,7% - Pourpoint: -42C - MRV(-35C): 25.000 - KV40: 78,2 - KV100: 13,3 - HTHS: 3,91 - HTFS: 2,86 - VII: 4,95% - A_Harman index: 0,9010
Ravenol VMP: TBN: 8,8 - SA: 0,7 - Flashpoint: 238C - VI: 179 - NOACK: 6,4% - Pourpoint: -60C - MRV(-35C): 12.000 - KV40: 66,3 - KV100: 11,9 - HTHS: 3,7 - HTFS: 2,89 - VII: 3,62% - A_Harman index: 0,9277
However the noise-reducing effect wore off after around 3.5K miles and the noise came right back. So I'm guessing the oil sheared down in that time enough to cause this (I can't prove this, idk where to do a UOA in Europe). Going with this logic, I figure a slightly thicker oil may help, so I've been looking at Ravenol SVS, which is a 5W40 with API SP, ACEA A3/B4, BMW LL-01, MB 229.5 and Porche A40 all recommended with no approvals(??). Ravenol also promises this particular oil to be very good at cleaning, although they don't mention how this is achieved (esters?). This oil is also somehow identical to Ravenol HST, sans the NOACK value. While the higher viscosity sounds good, I'm worried if I'd be sacrificing cold performace, since Honda really seems to love 0W oils in general. I don't expect lower than 10F temps though, so I'm not sure if 0W or 5W really matters. I've also been looking at Ravenol VMP, a mighty impressive oil, however I don't need a Mid SAPS oil, since no DPF, so I'm not sure if it's worth it.
I know y'all love the M1 FS 0W40, so I'm willing to try it, though there have been mixed reports on this very issue.
Here's the stats for nerds:
Ravenol SSO: TBN: 10,5 - SA: 1,1 - Flashpoint: 236C - VI: 173 - NOACK: 7,7% - Pourpoint: -60C - MRV(-40C): 17.400 - KV40: 68,6 - KV100: 12,0 - HTHS: 3,57 - HTFS: 2,61 - VII: 4,89% - A_Harman index: 0,9022
Ravenol SVS: TBN: 12,0 - SA: 1,19 - Flashpoint: 240C - VI: 173 - NOACK: 8,7% - Pourpoint: -42C - MRV(-35C): 25.000 - KV40: 78,2 - KV100: 13,3 - HTHS: 3,91 - HTFS: 2,86 - VII: 4,95% - A_Harman index: 0,9010
Ravenol VMP: TBN: 8,8 - SA: 0,7 - Flashpoint: 238C - VI: 179 - NOACK: 6,4% - Pourpoint: -60C - MRV(-35C): 12.000 - KV40: 66,3 - KV100: 11,9 - HTHS: 3,7 - HTFS: 2,89 - VII: 3,62% - A_Harman index: 0,9277